fix: name an archive the resolver cannot read

scripts/common.py

@@ -784,6 +784,20 @@ def _by_affinity(paths: list[str], file_entry: dict, dest_hint: str) -> list[str
     return sorted(paths, key=score, reverse=True)
 
 
+_unreadable_archives: set[str] = set()
+
+
+def _warn_unreadable_archive(path: str, exc: Exception) -> None:
+    """Say once that an archive on disk cannot be read.
+
+    Skipped in silence, a truncated ZIP came out as not_found or
+    hash_mismatch, which reads as a missing dump instead of a broken one.
+    """
+    if path not in _unreadable_archives:
+        _unreadable_archives.add(path)
+        print(f"warning: unreadable archive {path}: {exc}", file=sys.stderr)
+
+
 def resolve_local_file(
     file_entry: dict,
     db: dict,
@@ -1150,8 +1164,8 @@ def resolve_local_file(
                         composite = md5_composite(path).lower()
                         if composite in md5_set:
                             return path, "md5_composite_exact"
-                    except (zipfile.BadZipFile, OSError):
-                        pass
+                    except (zipfile.BadZipFile, OSError) as exc:
+                        _warn_unreadable_archive(path, exc)
                 if db_md5.lower() in md5_set and not composite_only:
                     return path, "md5_exact"
         # When zipped_file is set, only accept candidates that contain it
@@ -1163,8 +1177,8 @@ def resolve_local_file(
                         inner_names = {n.casefold() for n in zf.namelist()}
                         if zipped_file.casefold() in inner_names:
                             valid.append((path, m, size))
-                except (zipfile.BadZipFile, OSError):
-                    pass
+                except (zipfile.BadZipFile, OSError) as exc:
+                    _warn_unreadable_archive(path, exc)
             # The archive whose member carries the declared md5 is the one:
             # neogeo.zip is held twice, each with its own sfix.sfix, and the
             # first by name was returned as a mismatch while the other matched.

tests/test_audit_regressions.py

@@ -2723,5 +2723,27 @@ class HashMergeBackupsAreNotSources(unittest.TestCase):
         self.assertEqual(offenders, [])
 
 
+
+class AnUnreadableArchiveIsSaidOutLoud(unittest.TestCase):
+    """resolve_local_file skipped a ZIP it could not open without a word: a
+    truncated archive read as a missing dump (not_found) or a wrong one."""
+
+    def test_the_resolver_names_the_archive(self):
+        import common  # noqa: PLC0415
+
+        with tempfile.TemporaryDirectory(dir=ROOT / "tmp") as tmp:
+            broken = Path(tmp) / "neogeo.zip"
+            broken.write_bytes(b"PK\x03\x04 truncated")
+            sha1 = hashlib.sha1(broken.read_bytes()).hexdigest()
+            db = {"files": {sha1: {"path": str(broken), "name": "neogeo.zip", "sha1": sha1,
+                                   "md5": "0" * 32, "size": broken.stat().st_size}},
+                  "indexes": {"by_name": {"neogeo.zip": [sha1]}, "by_md5": {},
+                              "by_crc32": {}, "by_path_suffix": {}}}
+            entry = {"name": "neogeo.zip", "md5": "1" * 32, "zipped_file": "sp-s2.sp1"}
+            stderr = io.StringIO()
+            with contextlib.redirect_stderr(stderr):
+                common.resolve_local_file(entry, db)
+        self.assertIn(f"unreadable archive {broken}", stderr.getvalue())
+
 if __name__ == "__main__":
     unittest.main()